During the launch event at New York's Radio City Music Hall Thursday evening, Samsung spent a lot of time talking about the phone's various software upgrades, such as S Health, Story Album, and WatchOn. But underneath all the software is a really slick piece of hardware.

That's important, because one big question is whether the Galaxy S4's hardware is enough of an upgrade over the existing Galaxy S III$189.99 at Amazon Wireless on its own. For quite some time now, the Samsung Galaxy S III has been our favorite smartphone on a variety of carriers, and still holds various Editors' Choice awards. We know the S4 is better on the hardware side; that much is obvious. But is it enough of a jump to warrant a possibly costly upgrade if you already own a Galaxy S III? What if you need a phone right this moment, and can't necessarily wait until April for the S4 to arrive? Let's look at the details, shall we?